Stabilization of oxidizable substances



Patented Apr. 4, 1944 STABILIZATION F OXIDIZABLE SUBSTANCES Loran 0.Buxton, Bellevlllc, N. 1., assignor to Na- V I tional 011 ProductsCompany, Ha

rrison, N. 1.,

a corporation of New Jersey No Drawing. Application August 8, 1940,

' Serial No. 351,909

30 Claims. (Cl- 252- 398) This invention relates to the production ofantioxidants and to the stabilization of oxidizable organic substances,primarily those of an oilyor fatty nature.

It is well known in the art that many oxidizable organic substances, e.g. oils, fats and waxes containing fatty acid radicals, as well as soapsthereof, tend to be deterimentally afiected by exposure to atmosphericconditions for prolonged periods of time. For example, many oils andfats tend to develop considerable rancidity and undesirable tastes andodors upon prolonged exposure to air. This instability of oils and fatstends to be accentuated by conventional refining processes since in manycases the refining destroys or removes the natural antioxidants contained in such substances. instability is particularly undesirable inconnection with fat-soluble vitamin-containing oils, since these oilsnot only show the typical tendency to'become rancid upon exposure toair, but also tend to lose a considerable portion of their valuablevitamin activity. Other oxidizable organic substances manifest theircharacteristic instabilities in difierent fashions, but in practicallyevery case their instability is highly undesirable.

As a result of the instability shown by many oxidizable organicsubstances, many attempts have been made to increase the resistance ofthese substances to the action of oxidizing influences. For example ithas been proposed to stabilize oils and fats by adding certain crudevegetable oils thereto, the theory being that since the crude vegetableoils suggested for use contain natural antioxidants, these antioxidantswould serve to stabilize the oils and fats. This proposal has, however,not met with any particular success because of the fact that since thevegetable oils do not contain very high percentages of the antioxidants,disproportionately large amounts of the oils have to be added tothe'substances to be stabilized in order to achieve the desiredantioxidant effect. Several proposals have been advanced designed torecover valuable fractions from vegetable oils, but there has been noimportant success achieved along these lines with regard to theproduction of effective antioxidants therefrom; as a matter of fact, theart has generally believed that the vegetable meals, not the oilsexpressed therefrom, were the most suitable source of antioxidants andhas turned away from the idea of recovering antioxidants from such oils.

It has been suggested that solvents, such as This characteristic ethylalcohol, would be capable of extracting effective antioxidants fromoil-free vegetable meals. This proposal has several disadvantages. Inthe first place, the antioxidants extracted from the meals are generallynot completely oil-soluble, so that in some cases it is not possible toform completely homogeneous mixtures of these antioxidants withsubstances such as oils and fats. In the second place, the antioxidantsextracted from vegetable meals may have extremely dark colors andunpleasant odors and are generally obtained in very poor yields. Theresult of these disadvantages has been that the suggested method has notmet with any substantial degree of commercial success. I

It has also been proposed to recover antioxidants from vegetable oils bysaponifying the oils, separating the unsaponiflable portions of the oilsand recovering antioxidants from these unsaponifiable portions bysuccessive extractions and fractionations. This proposal has likewisenot been commercially successful because it envaluable vegetable oils,thereby rendering the process highly uneconomical, and because thesaponification probably destroys the antioxidant properties of certainof the materials contained in the oils; moreover, the necessity forcarrying out a. number of extraction and fractionation steps is clearlydisadvantageous.

' Because of the many-disadvantages inherent in prior processes for theproduction of antioxidants, there is still a considerable demand in theindustry for a simple, economical and ei fective method for preparingantioxidants which will accomplish the desired results. Furthermore,because of the tremendous recent development in the production and useof fat-soluble vitamin-containing oils, the need for such antioxidantshas become particularly acute due to the well known instability ofvitamins contained in such oils.

It is an object of this invention to provide stabilized oxidizableorganic substances resistant to the action of atmospheric conditions.

It is a more specific object of this invention to provide antioxidantscapable of stabilizing fatsoluble vitamin-containing oils.

Another object of this invention is to provide a simple and economicalprocess for the production of highly effective antioxidants.

I have made the surprising discovery that highly effective antioxidantsmay be economically produced from fatty materials with which they areassociated by subjecting fatty materials containing natural antioxidantsto solvent extraction with a suitable solvent, whereby the antioxidantsbecome concentrated in the solvent extract. My discovery is particularlyapplicable to the recovery of antioxidants from fatty oils such asvegetable and fish oils, since, contrary to all expectations, Ihavefound that solvent extraction of such materials yields productscontaining antioxidants in extremely active condition. I have furtherfound that the extracts recovered from fatty materials may be blendedwith oxidizable organic substances to form mixtures extremely resistantto deteriorative oxidation. My invention is primarily concerned with thestabilization of oxidizable organic substances of an oily or fattynature, since my antioxidants may be easily blended with such substancesto form completely homogeneous, stable mixtures. A preferred embodimentof my invention involves the stabilization of fat-solublevitamin-containing oils, since the addition of my extracts to such oilsnot only prevents the development of undesirable rancidity anddiscoloration, but stabilizes the vitamin content of the oils so thatthere is relatively little destruction of either the .vitamin A or Dcontained in the oils even after prolonged exposure to atmosphericconditions. My novel process'has the additional advantage that theresidual fatty materials from which the antioxidants have been extractedare more valuable than the fatty materials originally treated, since acertain amount of refining takes place due to a substantial removal ofcolor and odor along withconstituents responsible for the production ofbreak; thus my invention not only yields valuable antioxidants, but alsoproduces refined fattymaterials suitable for a wide variety of purposes.The yields obtained it is to be understood that other fatty materialsmay be used if desired.

As hereinabove pointed out, the antioxidants are recovered from fattymaterials with which they are associated by extraction with a suitablesolvent. The solvent employed in accordance with my invention may beselected from a large number of aliphatic solvents found to be useful asa result of extensive experimentation; the choice of the solvent willdepend to some extent upon the properties of the material to be treated,as will become more evident from the detailed dein accordance with myprocess are excellent and the solvents employed are all readilyavailable and comparatively inexpensive; as a result, my novel processfor the preparation of antioxidants is extremely economical.

The fatty materials from which the antioxidants are extracted inaccordance with my invention may be any fatty material containingnaturally occurring antioxidants, or mixtures thereof; preferably crudematerials containing such antioxidants are, employed. The. term fattymaterial" is used throughout the specification and claims to includeoils, fats and waxes containing fatty acid radicals. There are many suclmaterials containing natural antioxidants known to the art. Thus,vegetable oils and fats, such as soybean oil, wheat germ oil, corn germoil, corn oil, oat oil, rye oll, olive oil, sesame oil, cottonseed oil,palm oil, cocoa butter, palm kernel oil, coconut oil. rice oil. ricegerm oil, linseed oil, oiticica oil, teaseed oil, perilla oil, alfalfaseed oil, celery seed oil, flax seed oil, groundnut oil,

hemp seed oil, kapok oil, mustard seed oil, rape seed oil, poppy seedoil, sunflower seed oil, pumpkin seed oil, melon seed oils, peanut oiland the like may be treated. Another group of fatty materials which maybe employed is the fish liver oils, such as cod liver oil, tuna liveroil halibut liver oil, shark liver oil, etc., as well as other marineoils, such as menhaden oil, herring oil and sardine oil. .Other oilswhich may be treated in accordance with my invention are tomato seedoil. grape seed oil. peach kernel oil, egg oil and whale oil'. I preferto produce my antioxidants from vegetable oils, and in' the detaileddescription hereinafter given particular reference will be made to thetreatment of such oils; however scription hereinafter given. My resultshave indicated that the solvents preferably employed are members of wellrecognized chemical classes; I

have also found that the number of carbon atoms in the solvent to beused is a particularly important factor in determining the availabilitythereof for use in the practice of my invention. The following tableembodies the results of my experiments and sets forth the classes ofsolvents which I have found to be particularly useful in the recovery ofantioxidants:

Table I l. Aliphatic and allcyclic monohydroxy alcohols containing from3 to 6 carbon atoms.

2. Esters formed by the reaction of aliphatic and alicyclic alcoholswith aliphatic monocarboxylic acids, said esters containing not morethan 8 carbon atoms.

3. Aliphatic and alicyclic aldehydes containing not more than 6 carbonatoms.

4. Aliphatic ketones containing not more than 6 carbon atoms.

Solvents falling in the classes above listed are all liquid aliphaticorganic compounds having the properties of being miscible with fattymaterials at temperatures above room temperature, i. e. 20 to 25 C., andpartially immiscible therewith at temperatures substantially below roomtemperature, and my experiments have shown that solvents falling withinthis class of compounds may be used in the practice of my invention. Inaddition it will be noted that my preferred solvents possess relativelylow freezing points.

- In orderto more fully illustrate the nature of the solvents which Imay employ, a partial list thereof is herewith given; it is to beunderstood. however, that this list is not intended to be complete, butis merely illustrative of the solvents which may be employed' Thus Ihave found that the following solvents may be used: n-propyl alcohol.isopropyl alcohol, n-butyl alcohol, n-amyl alcohol, isoamyl alcohol,secondary amyl alcohol, furfuryl alcohol, allyl alcohol, diacetonealcohol, B-hydroxy ethyl acetate, methyl formate, ethyl formate, ethylacetate, methyl acetate, isopropyl acetate, glycol diformate, glycoldiacetate, methyl levulinate, ethyl levulinate, methyl aceto acetate,ethyl aceto acetate, methyl furoate, vinyl acetate, furfural,propionaldehyde, crotonaldehyde, acetone, methyl ethyl ketone, acetonylacetone and propylene chlorhydrin. Mixtures of these solvents may alsobe used. It will be noted that all these solvents belong to that classof aliphatic organic compounds which have the properties of beingmiscible with fatty oils at temperatures above room temperature andpartially immiscible therewith at temperatures substantially below roomtemperature; furthermore, itv will be noted that the majority of thesesolvents have relatively low freezing points.

Occasionally it may be found that certain of the solvents hereinabovementioned may be too iniscible with some oi. the fatty materials whichmay be treated by my invention to efiect a separationo! antioxidantstherefrom; thus, for

example, acetone is too miscible with many fatty materials to accomplishthe purposes of this invention. However, this condition may be easilycorrected by diluting the solvent either with a small amount 'of wateror with some liquid aliphatic organic solvent relatively immiscible withfatty materials. In general it may be said that the effect of dilutingany of the above solvents with water will be to render the'solvent moreimmiscible with fatty materials, so that ii diiiiculty is encountered ineflecting proper s'epara'-- tion or the antioxidant extracts from thefatty materials, this dimcu'lty may generally be overcome by theaddition of a small amount or water to the solvent. 3

The solvents I prefer to employ in the practice of my invention are thealiphatic alcohols containing from-3 to 6 carbon atoms; of thesesolvents isopropanol and diacetone alcohol have proved to be the mostsuccessful. The presence of the hydroxyl group seems to impart to thesesolvents properties which make them particularly useful for my purposes;whether this factor is due to some activating influence possessed bythis group is not known.

In carrying out the extraction-of the anti oxidants from the oils withwhich they are asso--- ciated, the oil to be treated is first mixed withthe particular solvent to be employed. The relative proportion ofoil tosolvent may vary widely;

preferably the ratio 'of solvent to oil should be greater than one, andinmost cases mixtures containing between about 2% and about 25% oil aremost suitable. It is preferable to cause substantially all the oil ,todissolve in the solvent; when employing the preferred solvents of myinvention, completesolution is ordinarily effected most readily byheating the mixture to a temperature substantially above roomtemperature. However, it is not necessary to cause the oil to dissolvecompletely in the solvent, since highly mixture to temperaturessubstantially in excess of 175 C. if recovery of the vitamins isdesired.

.The antioxidant fraction extracted from the oil may be recovered in anysuitable manner..

When operating in accordance with the preferred embodiment of myinvention, 1. e. when the oil is completely dissolved in the solvent atsomewhat elevated temperatures, the recovery of the antioxidant extractis most conveniently accomplished by cooling the solution to atemperature substantially below room temperature, e. g. between about C.and about -'70 0., whereby two layers form. The layer which separatesfrom e the solvent will be found to consist chiefly of the with tainingrelatively large amounts of highly active antioxidants. If desired,watermay be added to the extract in order to precipitate some of theglycerides contained therein or some of the sterols may be removed;however, these steps are not essential, since the glycerides andst'erols do not inhibit the antioxidant properties of the extract.

amount of free fatty acids, these are preferably If the extract containsan excessive removed by treatment with alkali in a solvent medium or byother suitable methods. The extract ordinarily possesses thecharacteristic odor and color of the oil from which it is obtained andis generally slightly more viscous than the original oil. The testscarried out on vegetable distillation, whereby an extract is recoveredoonoil extracts indicate that the iodine values of the extracts aresubstantially lower than those of the original oils. if a ilsh liver oilis employed in the practice of my invention, it will be found that theextract contains a considerable portion of the vitamins concentratedtherein.

This process of extractihg fish liver oils issdlsclosed and specificallyclaimed in the co-pend I ing application of Dombrow, Serial No. 343 558,filed July 2, 1940, and hence I. do not intend to specifically claim theextraction of such oils in the instant case.

My novel antioxidants may be employed for the stabilization of alltypesof oxidizable organic substances, particularly those of a fattynature. 1. e. fatty oils, fats, waxes, soaps, vitamin co'ncentrates,etc. iThus Oils and fats of animal, vegetable or fish origin, such ascod liver oil. tuna liver oil, shark liver oil and other fish. liveroils, as well as vitamin concentrates or vitamincontaining fractionsobtained from such oils; corn oil, cotton seed oil, soybean oil andother vegetable oils; fats such as butter, margarine, lard, hydrogenatedsliortenings, palm oil, etc.; soaps of higher fatty acids; andcompositions containing such fatty materials as essential inextractadded to the fatty material to be stai portion of the original oilinsoluble in the solvent at the temperature at which the separation iscarried out. This portion generally has a considerably lighter colorthan the original oil and in many cases .has lost someof thecharacteristic odor of the original oil.- Furthermore, in most cases itwill be found that materials re sponsible for producing break have beenremoved from the oil by the extraction. Thus the residue from theextraction may be used for a gredients, e. g. food-emulsions such asmayon naise, may all be suitably stabilized in accordance with myinvention. Furthermore, substances such as sulfonat ed oils and othersulfonated fatty compounds, amides, mono and di glycerides and otherfatty substances which tend to become rancid upon exposure to air may betreated by my invention. The amount of the bilized may varyconsiderably, depending upon the activity of the extract and the degreeof instability of the fatty material; I have found that .oils or ratscontaining anywhere from about 0.1% to about 20%, preferably from about0.5% to about 5%, of my antioxidant extracts show striking improvementsin their stability.

My antioxidants are particularly adapted for the stabilization offat-soluble vitamin-conta n ing oils or concentrates, as well asvitamin-containing fractions recoverable from such products by vacuumdistillation, solvent extraction or other processes. This is extremelyfortunate, for antioxidants capable of stabilizing such products havenot as yet been made avail able on a wide scale. My antioxidants may beadded to such materials in any suitable amount without impartingundesirable color, odor, taste or toxicity thereto; furthermore theincorporastantially atlecting the activity of the antioxidants;moreover, the heatingof vitamin-containing oils stabilized by theaddition of my extracts does not substantially reduce the vitaminactivity of the oils. As a matter of fact, 1 have found that by addingthe antioxidant extracts of my invention to substances of a fatty naturehaving undesirable tastes and odors and subsequently heating themixtures to elevated temperat'ures, e. g. 110 to 130. C., theundesirable tastes and odors of the substances are substantiallyminimized.

- In order to illustrate the improved stability displayed byvitamin-containing oils stabilized in accordance with myinvention, thefollowing table is submitted, which shows the relative stabillties ofcrude shark liver oil and shark liver oilreflned to remove its odor,color and taste contrasted with these same oils conta ning 5% of one ofthe extracts of my invention. These tests were conducted by maintainingthe samples at a constant temperature of 345 C. in the presence of airfor the indicatedlnumber of days and then measuring the percentage ofthe vita min A destroyed.

The above table clearly demonstrates the superiority ofvitamin-containing oils stabilized by.

the addition of my novel antioxidants. It will be noted that thestabilized refined oils of my invention are even more stable thanordinary crude shark liver oil, so that it is evident my inventionpermits the production of vitamin oils having no undesirable color,odorortaste, and which are, nevertheless, exceedingly stable tooxidizing influences.

Table H Percent vitsrinin A destroyed n- Sample 7 days days days daysdays Crude shark liver oil containing llti,000 A gm 8. 2. 20. 2 32. 746. 2 68 Crude shark liver oil containing 5% soybean oil extrl'ct 2. 258. 6 10.9 24. 2 27.1 Refined shark liver oil containing 108,500 A gm 42.6 73.1 Refined shark liver oil containing 5% wheat germ oil extract 0.47 4. 2 l5. 1 25. 2 37. 9

Refined shark liver oil containing 5% soybean oil extract 6. 66 22. 132. 2 42. 1

Refined shark liver oil containing Q corn germ oil extract l. 87 12. 325. 2 40. 5 52. 9

.C. in a nitrogen atmosphere, whereby a homo- While it is to beunderstood that the process a fatty material containing naturalantioxidants with one of the above solvents mixed with-a mutual solvent,such as ether or ethylene dihereinabove described ispreferablyfemployed,lmy invention may also bezcarried out by contactingchloride, so as to form a-homogeneous solution 1 of the fatty materialin the solvent mixture and geneous solution formed.

. 2,345,576 tionof my antioxidants" in such vitamin-conplace. Theantioxidants are concentrated in the solvent layer and may be recoveredtherefrom.

A,modiflcation ,of the process hereinabove described which I have foundto be particularly successful -involves extracting a mixture of a:flsh'liver oil and a vegetable oil containing natural antioxidants withone of the above solvents. As pointed out in the copending Dombrowapplication hereinabove referred'to, the extraction of the fish liveroil effects a concentration of the vitamins in the solvent; furthermorethe anti other materials known to the art may be stabilized by treatmentwith. my novel extracts.

The following examples are illustrative of the method oi producing theextracts oi. my inven tion; amounts are given imparts by weight.

Example I 98 parts of cold pressed wheat germ oil having an iodine valueof 127 were mixed with 320 parts of 91% isopropanol and the mixtureheated to about 62 C. in a nitrogen atmosphere, whereby a homogeneoussolution was formed. The solution was then cooled to i-JB" C. and thesolvent layer withdrawn and filtered. The residue was Ire-extracted with91% isopropanol as hereinabove described and the solvent layerrecovered. The isopropanol was then evaporated from the solvent layersby vacuum distillation in the presence of nitrogen. Both extracts showedstrong antioxidant properties. The iodine values of the first and secondextracts were 119 and 124, respectively.

Example [I panol from the extracts itwas found that each.

extract contained highly active -antioxidants.

The iodine values oi the first and second extracts v were 110.2 and113.2, respectively.

' ,,E.mmpie III parts of virgin soybean oil having an iodine value of126 were mixed with 1600 parts of 99% isopropanol and the'mixture heatedto about 50 The solution was then cooled to ---18 C. and the solventlayer withdrawn and-filtered. The residue was re-extracted with 99%isopropanol as hereinabove described. Upon evaporation of theisopropanol from the extracts. it was found that both extracts had stron.antioxidant properties. The iodine valuesof the first and secondextracts were 119.3 and 117.9, respectively.

Example IV 500 parts f virgin soybean oil were dissolved in 1800 partsofethyl acetate heated to 60 C. in a" nitrogen atmosphere. The solutionwas then cooled to 18 C. and the solvent layer withdrawn andseparated;-Upon evaporation of the ethyl acetate from the solvent layer, it wasfound that the extract possessed strong antioxidant properties.

' Example V 500 parts of crudecom oilhaving an'iodine value of -11'l.8were dissolved in 1600 parts of aec svc gradually'cooled to --15 0. Thesolvent layer was withdrawn and the insoluble residue was thenextractedwith two additional portions of isopro- 91% isopropanol heatedto 60 '0. in a nitrogen atmosphere; The solution was then cooled to 18and the solvent layer withdrawn and separated. The residuewas thenre-extracted with 3 additional portions of 91% isopropanoh Uponevaporation of the isopropanol from the extracts,

it was found that the majority of the antioxidants were concentrated inthe first two extracts, the third and fourth extracts havingcomparatively little antioxidant value. The iodine values of' the firstand second extracts were .105 and 115, re-

spectively.

' Example VI 4 5 parts of cottonseed e11 refined, by treatment withdecolorizing carbon were mixed with 1500 parts of refluxing 91isopropa'nol in a nitrogen atmosphere, whereby a homogeneous solutionformed. The solution was then cooled to was found that the extractpossessed oxidant properties.

Example VI] 500 parts of crude peanut oil were added gradually to 1800partsof hot diacetone alcoholin a nitrogen atmosphere, whereby ahomogeneous strong antisolution was formed. The solution was then cooledto -18 C. and the solvent layer was withdrawn and filtered. Uponevaporation of the diacetone alcohol, it was found that the extractpossessed strong antioxidant properties.

Example VIII -18- C. and the solvent layerwas withdrawn and filtered.Upon evaporation of the solvent it 500 parts of raw linseed oil wereadded to 1600 parts of hot acetone containing about 5% water in anitrogen atmosphere, whereby a homogeneous solution formed. Thissolution was then cooled to about 18 C. andthe solvent layer waswithdrawn and filtered. Upon evaporation of the acetone and water, anextract having strong antioxldent properties was recovered.

l Example IX 100 parts of tomato seed oil were mixed with 400 parts of91% isopropanol in a'nitrogen atmospher'e and the mixture heated toabout (3., whereby a homogeneous solution formed. The solution was thencooled to about -18 C. and the solvent layer was withdrawn and filtered.Upon evaporation of the isopropanol; it was found that the extractpossessedstrong antioxidant properties.

In order to specifically illustrate the improved nature. of the residualoil remaining after the antioxidant extract has been removed, thefollowing example is given:

Example X 200 parts of virgin soybean oil were dissolved in 640 parts of99% isopropanol heated to 60 C. in a nitrogen atmosphere and thesolution was panol. The residual oil remaining from the extractionsshowed no darkening even upon heating to 200 or 300 C. This oil was anexcellent reflnednon-break"oil.

From the above description it will be evident that my invention providesanew and highly useful method for the recovery of naturally 00- curringantioxidants from fatty materials with which they are associated. Myinvention provides a process which is highly economical and whichfurnishes completely oil-soluble antioxidents; furthermore, since myprocess does not involve subjecting the fatty material being treated tosaponification or any other chemical change, the residual material isparticularly valuable for awide variety of purposes after the removal ofthe antioxidants therefrom. Furthermore my invention provides a highlyuseful process for the stabilization of fat-soluble vitamincontainingoils and thus satisfies the demand of the industry for such products. Myprocess ac complishes the separation of antioxidants from materialswhich were thought to contain a rela tively small quantity of theseantioxidants, thereby enhancing the value of the fatty materials bypermitting the production of other valuable lay-products therefrom.Because of these factors it will be evident that my invention 'will beextremely useful to all those engaged in the production andstabilization of fatty materials.

Since certain changes in carrying out the above process and certainmodifications in. compositions which embody the invention may be I madewithout departing from its scope, it is intended that all mattercontained in the above description shall be interpreted as illustrativeand not in a limiting sense with fatty materials at mmperaturessubstantially below room temperature, the ratio of sol vent to oil beinggreater than. one, cool ng the mass to a temperature within the range of0 C. to -70 0. whereby layers are formed and cop arating the solventlayer containing the highly active antioxidant extract from theremainder of the fatty material.

2. A process for obtaining antioxidants from vegetable oils containingnatural antioxidants,

which comprises contacting a vegetable oil containing naturalantioxidants with a solvent selected from'the classes listed in Table Iat a temperature above room temperature, cooling the mass to atemperature within the range of 0 C. to --l0 0. whereby layers areformed and soparating the solvent layer containing the highly activeantioxidant extract the remainder of the oil.

3. A process for obtaining antioxidants from vegetable oils containingnatural antioxidants, which comprises contacting a vegetable oilcontaining natural antioxidants with a solvent so lected iron; theclasses listed temperature below formed and separating the refined oillayer from K Table 1 at a temperature above ro'om tempe ature, the ratioof solvent to all being greater than one, cooling the mass". to atemperature within the range of 0 C. to -70 0. whereby layers are formedand separating the solvent layer solution, containing the highly activeantioxidant extract ,from the remainder oi the oil.

4. A process for obtaining antioxidants from vegetable oils containingnatural antioxidants, which comprises contacting a vegetable oilcontaining natural antioxidants with an aliphatic monohydroxy alcoholcontaining from 3 to 6 carbon atoms at a temperatureabove roomtemperature, cooling the mass to a. temperature below 0 C. wherebylayers arejormed and separating the solvent layer containing the highlyactive antioxidaht extract from the remainder or the Oil. 7 v V s I.

5. A process for obtaining antioxidants from wheat germ oil, whichcomprises contacting v I wheat germ oil with isopropanol at atemperature above room temperature so as to form a solution of the oilin the 'isopropanol, cooling the solution to a temperature below 0 C.whereby layers are formed and separating the solvent layer containingthe highly active antioxidant extract from the remainder of the oil.

6. A process for obtaining antioxidants from corn germ oil, whichcomprises contacting corn germ oil with isopropanol at a temperatureabove room temperature so as'to form a solution of the oil in theisopropanol, cooling the solution to a temperature below 0 C. wherebylayers are formed and separating the solvent layer containing the highlyactive antioxidant extract from theremainder of the oil.

7. A process for obtaining antioxidants from soybean oil, whichcomprises contacting soybeanoil with isopropanol at a temperature aboveroom temperature so as to form' a solution of the oil in theisopropanol, cooling the solution to a temperature below 0 C. wherebylayers are formed and separating the solvent layer containing the highlyactive antioxidant extract from the remainder of the oil.

8. A'process for the recovery of antioxidants y from fatty materialswith which they are associated,, which comprises contacting a mixture offish liver oils and vegetable oils containing nat-- ural antioxidantswith a solvent selected from the classes listed in Table-I at atemperature above room temperature, cooling the mass to a temperaturewithin the range of 0 C. to -'70 C. whereby layers are formed andseparating the solvent layer containing the highly active anti- -oxidantextract from the remainder of the oil.

- 9."-;A process for obtaining a refined "nonbreak oil from a vegetableoil, which comprises contacting a vegetable oil with a solvent selectedfrom the classes listed in Table I at a temperature above'roomtemperature, cooling the mass to a C. whereby layers are the solventlayer.

10. A process for obtaining a refined non break oil from a vegetableoil, which comprises contacting a. vegetable oil with isopropanol at a atemperature above room temperature, cooling the solution to atemperature below 0 C- whereby layers are formed and separating therefined oil layer from the solvent layer.-

11. A highly active natural antioxidant con centrate prepared inaccordance with the process set forth in claim 1.

' assaere' '12. a highly active natural antioxidant conv centrateprepared in accordance with the process set forth in claim 2.

13. a highly active-natural'antioxidant con- ,centrate prepared inaccordance with the process set forth in claim 3. I

1a. A highly active natural antioxidant concentrate prepared inaccordance with the process 7 set forth in claim 4.

1.5. A hi hly active natural antioxidant concentrate prepared inaccordance with the process set forth in claim 5.

16. highly active natural antioxidant con centrate prepared inaccordance with the process set forth in claim 6.

17. A highly active natural antioxidant concentrate prepared inaccordance with the process.

set forth in claim 7.

l8. highly active natural ahtioxidant con! 7 centrate prepared inaccordance set forth in claim 8. I

19. An oxidizable organic substance stabilized against oxidation by thepresence therein of a natural antioxidant concentrate prepared in acwiththe process cordance with the process set forth inf claim 1.,

20. An oxidizable organic substance of a'iatty nature stabilized againstoxidation by the'presencc therein or a naturalantioxidant concentrateprepared in accordance with the process set forth in claim 1. i

21. A fat-soluble vitamin-containing substance stabilized againstoxidation by the presence therein of a natural antioxidant concentrateprepared in accordance with the process of claim 1.

22. An oxidizabie organic substance stabilized against oxidation by thepresence therein of a natural antioxidant concentrate prepared inaccordance with the process set forth in claim 2. 23. An oxidizableorganic substance of a fatty nature stabilized against oxidation by thepresence therein of a natural antioxidant concentrate prepared inaccordance with the process set forth in claim 2. I

24. A fat-soluble vitamin-containing substance stabilized againstoxidation by the presence therein of a natural antioxidant concentrateprepared in accordance with the process of claim 2.

25. A rat-soluble vitamin-containinz substance stabilized againstoxidation by the presence there in of a natural antioxidant concentrateprepared in accordance with the process of claimB.

26. A fat-soluble vitamin-containing substance stabilized againstoxidation by the presence therein of a natural antioxidant concentrateprepared in accordance with the process of claim '4. 27. A fat-solublevitamin-containing substance stabilized against oxidation by thepresencetherein of a natural antioxidant concentrate prepared inaccordance with the process of claim 5.

28. A fat-soluble vitamin-containing substance 1 stabilized againstoxidation by the presence therein of a natural antioxidant concentrateprepared. in accordance with the process of claim 6.

2.). A iat-solublevitamin-containing substance stabilized againstoxidation by the presence therein of a natural antioxidant concentrateprepared in accordance with the process oi claim '7. v

30. A fat-soluble vitamin-containing substance stabilized againstoxidation by the presence.

therein of a natural antioxidant concentrate prepared in accordance withthe process oi claim 8.

oam 0. items.

